In alternator, during hunting when the speed becomes super synchronous, the damper bars develop
In alternator, during hunting when the speed becomes super synchronous, the damper bars develop Correct Answer induction generator torque
Hunting is the phenomenon of the synchronous machines which oscillates at about its new equilibrium position i.e. the synchronous machines rotates at other than synchronous speed.
Damper windings are used to prevent hunting of synchronous generator or to reduces oscillations of the rotor when the motor deviates from synchronism.
When the rotor rotates at synchronous speed, there is no relative motion between armature flux and damper winding (since damper winding is placed on rotor). Therefore, EMF induced in the damper bars is zero means current through the damper bars equal to zero and hence damper winding torque production is zero.
When the rotor speed is more than synchronous speed, induction generator torque will be produced in the opposite direction to synchronous machine torque such that speed becomes nearer to synchronous speed.
When the rotor speed is less than synchronous speed, induction motor torque will be produced in the same direction of synchronous machine torque such that speed becomes nearer to synchronous speed.